With the merge of #43176 Profile names were heavily restricted. While I can understand that this change is required due to the errors of parsing mentioned in a separate issue, it was a surprise to suddenly have . be invalid in the Profile.
In trying to debug this I cross referenced the following. - Spring Boot Profiles Docs - Spring Framework Profile Mentions - Spring Boot Release Summary - The full wiki page does list the breaking change. - Even Profile Javadocs
Another developer found it was 3.5.0's changes that caused the break.
With automatic dependency updates this resulted in sudden break for a few teams. It would have been beneficial to have a version which logs a very loud warning before a breaking version. Breaking in 3.5.1 or 3.6.0 would have been fine. Additionally the profile restrictions should have been documented in at least the main documentation before the release.
TLDR : Warning Version and then a Breaking Version would have been appreciated.
Comment From: philwebb
Thanks for the feedback @Crain-32. It looks like we might have been too aggressive with this feature and it's causing more issues than we anticipated. It's especially unfortunate that there's no easy way to opt-out of profile validation.
I'm going to investigate options to see if we can improve things for 3.5.1